Embodiments of the present disclosure generally relate to methods and devices for controlling a left univentricular pacing therapy.
Clinical studies related to cardiac pacing have shown that an optimal atrio-ventricular pacing delay (e.g., AV delay or PV delay) and/or an optimal interventricular pacing delay (e.g., VV delay) can improve cardiac performance. However, such optimal delays depend on a variety of factors that may vary over time. Thus, what is “optimal” may vary over time. An optimization of AV/PV pacing delay and/or VV pacing delay may occur at implantation and sometimes, a re-optimization may occur during a follow-up consultation. While such optimizations are beneficial, the benefits may not be long lasting due to changes in various factors related to device and/or cardiac function. Various systems and methods are provided for allowing a pacemaker or IMD to determine and/or adjust AV/PV/VV pacing delays so as to help maintain the pacing delays at optimal values. In particular, techniques were set forth for exploiting various interventricular conduction delays to determine optimal AV/PV/VV pacing delays. Techniques were also set forth for exploiting the VV delays to determine which ventricles should be paced—the left ventricle (LV), the right ventricle (RV), both ventricles, or neither.
Other techniques have been set forth for determining AV/PV delays based on inter-atrial conduction delays and interventricular conduction delays. In particular, see U.S. Pat. No. 7,248,925, to Bruhns et al., entitled “System and Method for Determining Optimal Atrioventricular Delay based on Intrinsic Conduction Delays,” which is fully incorporated by reference herein.
Most conventional pacing algorithms call for pacing in the right ventricle (RV) alone or in combination with left ventricular (LV) pacing. However, certain patients may exhibit circumstances where RV pacing may not be necessary. For example, patients may exhibit atria-ventricular conduction delays in certain ranges where pacing in the left ventricle is effective without a need for RV pacing.